Reverse link power control for an OFDMA system

Abstract

Techniques for performing power control of multiple channels sent using multiple radio technologies are described. The transmit power of a reference channel, sent using a first radio technology (e.g., CDMA), is adjusted to achieve a target level of performance (e.g., a target erasure rate) for the reference channel. The transmit power of a data channel, sent using a second radio technology (e.g., OFDMA), is adjusted based on the transmit power of the reference channel. In one power control scheme, a reference power spectral density (PSD) level is determined based on the transmit power of the reference channel. A transmit PSD delta for the data channel is adjusted based on interference estimates. A transmit PSD of the data channel is determined based on the reference PSD level and the transmit PSD delta. The transmit power of the data channel is then set to achieve the transmit PSD for the data channel.

1. An apparatus comprising:
 at least one processor to transmit a first signal via a reference channel using a first radio technology, to transmit a second signal via a second channel using a second radio technology, to adjust a transmit power of the reference channel, at least in part, to achieve a target level of performance for the reference channel, and to adjust a transmit power of the second channel based, at least in part, on a transmit power spectral density (PSD) of the reference channel; and 
 a memory coupled to the at least one processor. 
 
     
     
       2. The apparatus of  claim 1 , wherein the first radio technology comprises Code Division Multiple Access (CDMA) and the second radio technology comprises Orthogonal Frequency Division Multiple Access (OFDMA). 
     
     
       3. The apparatus of  claim 1 , wherein the reference channel carries signaling and the second channel carries traffic data. 
     
     
       4. The apparatus of  claim 1 , the at least one processor to receive power control (PC) commands for the reference channel and to adjust the transmit power of the reference channel based, at least in part, on the received PC commands. 
     
     
       5. The apparatus of  claim 4 , wherein the PC commands are generated, at least in part, to achieve a target received signal quality for the reference channel. 
     
     
       6. The apparatus of  claim 1 , wherein the target level of performance for the reference channel is based, at least in part, on a target erasure rate for one or more codewords sent on the reference channel. 
     
     
       7. The apparatus of  claim 1 , the at least one processor to receive erasure indications for one or more codewords sent on the reference channel and to adjust the transmit power of the reference channel based, at least in part, on the one or more erasure indications. 
     
     
       8. The apparatus of  claim 1 , the at least one processor to increase the transmit power of the reference channel by an up step in response to a codeword sent on the reference channel being detected as an erasure, and to decrease the transmit power of the reference channel by a down step in response to the codeword sent being detected as non-erased. 
     
     
       9. The apparatus of  claim 8 , wherein the up and down steps are selected based, at least in part, on a target erasure rate for the reference channel. 
     
     
       10. The apparatus of  claim 1 , the at least one processor to adjust a power spectral density (PSD) delta based, at least in part, on one or more interference estimates and to set the transmit power of the second channel based, at least in part, on the PSD delta. 
     
     
       11. The apparatus of  claim 1 , the at least one processor to adjust a transmit power spectral density (PSD) delta based, at least in part, on one or more interference estimates, to determine a transmit PSD of the second channel based, at least in part, on the transmit PSD delta and the transmit PSD of the reference channel, and to set the transmit power of the second channel, at least in part, to achieve the transmit PSD of the second channel. 
     
     
       12. The apparatus of  claim 1 , wherein the reference channel carries channel quality indication (CQI) information. 
     
     
       13. A method comprising:
 sending a first signal via a reference channel using a first radio technology; 
 sending a second signal via a second channel using a second radio technology; 
 adjusting a transmit power of the reference channel, at least in part, to achieve a target level of performance for the reference channel; and 
 adjusting a transmit power of the second channel based, at least in part, on a transmit power spectral density (PSD) of the reference channel. 
 
     
     
       14. The method of  claim 13 , wherein the adjusting the transmit power of the reference channel comprises receiving one or more power control (PC) commands for the reference channel, and adjusting the transmit power of the reference channel based, at least in part, on the one or more PC commands. 
     
     
       15. The method of  claim 13 , wherein the adjusting the transmit power of the reference channel comprises receiving one or more erasure indications for one or more codewords sent on the reference channel, and adjusting the transmit power of the reference channel based, at least in part, on the one or more erasure indications. 
     
     
       16. The method of  claim 13 , wherein the adjusting the transmit power of the second channel comprises adjusting a power spectral density (PSD) delta based on one or more interference estimates, and setting the transmit power of the second channel based, at least in part, on the PSD delta. 
     
     
       17. An apparatus comprising:
 means for sending a first signal via a reference channel using a first radio technology; 
 means for sending a second signal via a second channel using a second radio technology; 
 means for adjusting a transmit power of the reference channel, at least in part, to achieve a target level of performance for the reference channel; and 
 means for adjusting a transmit power of the second channel based, at least in part, on a transmit power spectral density (PSD) of the reference channel. 
 
     
     
       18. The apparatus of  claim 17 , further comprising:
 means for receiving one or more power control (PC) commands for the reference channel, and means for adjusting the transmit power of the reference channel based, at least in part, on the one or more PC commands. 
 
     
     
       19. The apparatus of  claim 17 , further comprising:
 means for receiving one or more erasure indications for one or more codewords sent on the reference channel, and means for adjusting the transmit power of the reference channel based, at least in part, on the one or more erasure indications. 
 
     
     
       20. The apparatus of  claim 17 , further comprising:
 means for adjusting a power spectral density (PSD) delta based, at least in part, on one or more interference estimates, and means for setting the transmit power of the second channel based, at least in part, on the PSD delta. 
 
     
     
       21. An article comprising:
 a processor readable media having instructions stored thereon that are executable by one or more processors to initiate: 
 adjustment of a transmit power of a reference channel, the reference channel comprising a first signal being sent using a first radio, at least in part, to achieve a target level of performance for the reference channel; and 
 adjustment of a transmit power of a second channel, the second channel comprising a second signal being sent using a second radio technology, the transmit power of the second channel being adjusted based, at least in part, on a transmit power spectral density (PSD) of the reference channel. 
 
     
     
       22. An apparatus comprising: at least one processor to transmit a first signal via a reference channel using a first radio technology, to transmit a second signal via a second channel using a second radio technology, to adjust transmit power of the reference channel, at least in part, to achieve a target level of performance for the reference channel, and to adjust transmit power of the second channel based, at least in part, on the transmit power of the reference channel; and a memory coupled to the at least one processor, and the at least one processor further to adjust a transmit power spectral density (PSD) delta based, at least in part, on one or more interference estimates, to determine a transmit PSD of the second channel based, at least in part, on the transmit PSD delta and a transmit PSD of the reference channel, and to set the transmit power of the second channel, at least in part, to achieve the transmit PSD of the second channel. 
     
     
       23. The apparatus of  claim 22 , wherein the first radio technology comprises Code Division Multiple Access (CDMA) and the second radio technology comprises Orthogonal Frequency Division Multiple Access (OFDMA). 
     
     
       24. The apparatus of  claim 22 , wherein the reference channel carries signaling and the second channel carries traffic data. 
     
     
       25. The apparatus of  claim 22 , the at least one processor to receive power control (PC) commands for the reference channel and to adjust the transmit power of the reference channel based, at least in part, on the received PC commands. 
     
     
       26. The apparatus of  claim 25 , wherein the PC commands are generated, at least in part, to achieve a target received signal quality for the reference channel. 
     
     
       27. The apparatus of  claim 22 , wherein the target level of performance for the reference channel is based, at least in part, on a target erasure rate for one or more codewords sent on the reference channel. 
     
     
       28. The apparatus of  claim 22 , the at least one processor to receive erasure indications for one or more codewords sent on the reference channel and to adjust the transmit power of the reference channel based, at least in part, on the one or more erasure indications. 
     
     
       29. The apparatus of  claim 22 , the at least one processor to increase the transmit power of the reference channel by an up step in response to a codeword sent on the reference channel being detected as an erasure, and to decrease the transmit power of the reference channel by a down step in response to the codeword sent being detected as non-erased. 
     
     
       30. The apparatus of  claim 29 , wherein the up and down steps are selected based, at least in part, on a target erasure rate for the reference channel. 
     
     
       31. The apparatus of  claim 22 , wherein the reference channel carries channel quality indication (CQI) information. 
     
     
       32. A method comprising:
 sending a first signal via a reference channel using a first radio technology; 
 sending a second signal via a second channel using a second radio technology; 
 adjusting transmit power of the reference channel, at least in part, to achieve a target level of performance for the reference channel; 
 adjusting transmit power of the second channel based, at least in part, on the transmit power of the reference channel; 
 adjusting a transmit power spectral density (PSD) delta based, at least in part, on one or more interference estimates; 
 determining a transmit PSD of the second channel based, at least in part, on the transmit PSD delta and a transmit PSD of the reference channel; and 
 setting the transmit power of the second channel, at least in part, to achieve the transmit PSD of the second channel. 
 
     
     
       33. The method of  claim 32 , wherein the first radio technology comprises Code Division Multiple Access (CDMA) and the second radio technology comprises Orthogonal Frequency Division Multiple Access (OFDMA). 
     
     
       34. The method of  claim 32 , wherein adjusting the transmit power of the reference channel comprises receiving one or more power control (PC) commands for the reference channel, and adjusting the transmit power of the reference channel based, at least in part, on the one or more PC commands. 
     
     
       35. The method of  claim 32 , wherein the adjusting the transmit power of the reference channel comprises receiving one or more erasure indications for one or more codewords sent on the reference channel, and adjusting the transmit power of the reference channel based, at least in part, on the one or more erasure indications. 
     
     
       36. The method of  claim 32 , wherein the adjusting the transmit power of the second channel comprises adjusting a delta based one or more interference estimates, and setting the transmit power of the second channel based, at least in part, on the transmit power of the reference channel and the delta. 
     
     
       37. An apparatus comprising:
 means for sending a first signal via a reference channel using a first radio technology; 
 means for sending a second signal via a second channel using a second radio technology; 
 means for adjusting transmit power of the reference channel, at least in part, to achieve a target level of performance for the reference channel; 
 means for adjusting transmit power of the second channel based on the transmit power of the reference channel; 
 means for adjusting a transmit power spectral density (PSD) delta based, at least in part, on one or more interference estimates; 
 means for determining a transmit PSD of the second channel based, at least in part, on the transmit PSD delta and a transmit PSD of the reference channel; and 
 means for setting the transmit power of the second channel, at least in part, to achieve the transmit PSD of the second channel. 
 
     
     
       38. The apparatus of  claim 37 , wherein the first radio technology comprises Code Division Multiple Access (CDMA) and the second radio technology comprises Orthogonal Frequency Division Multiple Access (OFDMA). 
     
     
       39. The apparatus of  claim 37 , further comprising:
 means for receiving one or more power control (PC) commands for the reference channel, and means for adjusting the transmit power of the reference channel based, at least in part, on the one or more PC commands. 
 
     
     
       40. The apparatus of  claim 37 , further comprising:
 means for receiving one or more erasure indications for one or more codewords sent on the reference channel, and means for adjusting the transmit power of the reference channel based, at least in part, on the one or more erasure indications. 
 
     
     
       41. The apparatus of  claim 37 , further comprising:
 means for adjusting a delta based, at least in part, on one or more interference estimates, and means for setting the transmit power of the second channel based, at least in part, on the transmit power of the reference channel and the delta. 
 
     
     
       42. An article comprising:
 a processor readable media having instructions stored thereon executable by one or more processors to initiate: 
 adjustment of a transmit power of a reference channel, the reference channel comprising a first signal being sent using a first radio technology, the transmit power of the reference channel being adjusted, at least in part, to achieve a target level of performance for the reference channel; 
 adjustment of a transmit power of a second channel, the second channel comprising a second signal being sent using a second radio technology, the transmit power of the second channel being adjusted based, at least in part, on the transmit power of the reference channel; 
 adjustment of a transmit power spectral density (PSD) delta based, at least in part, on one or more interference estimates; 
 determination of a transmit PSD of the second channel based, at least in part, on the transmit PSD delta and a transmit PSD of the reference channel; and 
 adjustment of the transmit power of the second channel, at least in part, to achieve the transmit PSD of the second channel.